i'm not sure there is an immediate threat to the united states. if they have a safe haven to train and arm and from which they can move around the globe to spread terrorism, it is just another venue for them. at the end of the day, even if you secure the information, what are we going to do about it? i understand what he's trying to do. it is necessary we try to identify them. >> we haven't had a major attack on the homeland since not -- since 9/11. how big of a concern is that when you have the semi-of brothers -- have the tsarnaev brothers, one facing the death penalty. we heard from the justice department. how big of a threat are these isolated incidents? these are just two brothers in communication with each other in no other network. guest: obviously they were converted along the way. it hadn't been turned to jihadist at the time. i do think that one off, the lone wolf, the individual or small group of individuals who have been pulled in and acknowledged, i think that is an one of the two major challenges the rest of the world are -- sadly th